Warning indicator for a camera

ABSTRACT

A camera having a recess for receiving a roll of film and a take-up mechanism for advancing the film, the film having registration holes along the edges thereof, is provided with a sprocketed wheel for engagement with the registration holes, the wheel advancing when the film is advanced by the take-up mechanism. The wheel is coupled to a mechanical flag, in one embodiment, and to an electronic indicator, in another embodiment, to warn the operator of the camera when the film is not advancing properly.

My invention relates to a warning system for a camera and moreparticularly to a warning indicator for a photographic-type cameraindicating the lack of proper advancement of the photographic film.

An objective of my invention is to provide an improved camera and moreparticularly to provide a camera with a warning indicator instructingthe operator of the camera that its film has not properly advanced.

These objects are achieved as is now described. The body of a camera ofthe type having a recess for receiving a roll or canister of film and amechanical take up mechanism for advancing the film is provided with awheel which turns in response to advancement of the film. In the case offilm having registration holes along its edges, this wheel may then be asprocketed wheel, the sprockets of which engage the registration holesin the film. The wheel is coupled, in one embodiment, via a mechanicallinkage and a release mechanism to a flag. The flag is disposed near theviewfinder and is visible in the viewfinder when the film is notproperly advanced. Alternatively, the flag may be located elsewhere inthe camera's body. Advancing the film causes the wheel to rotate, which,in turn, causes the flag to rotate or move to a non-obversable position,indicating that the film has advanced. The release mechanism ispreferably coupled to the shutter release button, thereby causing theflag to return to its warning position after each picture is taken.Alternatively, the release mechanism may be coupled to the button whichreleases the camera' s back (to provide acess to the camera's interior,especially to the film) whereby the flag will reappear when film isloaded into the camera.

In a second embodiment, the wheel is coupled to a detent which retractswhen the film advances. The detent cooperates with the film advancementmechanism to permit only partial advancement of the film advancementlever if the detent has not retracted in response to movement of thefilm. In this embodiment the warning signal is provided to the cameraoperator in the event of improper film advancement by reason of the factthat the film advancement lever cannot be fully rotated.

In a third embodiment the wheel is coupled to a first switch in anelectronic circuit. The circuit includes a flip-flop which is set by theoperation of a second switch which is either arranged to operate whenthe shutter release button is depressed or when the camera's back isopened. The first switch resets the flip-flop. The flip-flop causes awarning indicator to light when set.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed to be characteristic of my invention are setforth in the appended claims. The invention itself, however, as well asa preferred mode of use and further objects and advantages thereof, willbe best understood by reference to the following detailed descriptionwhen read in conjunction with the accompanying drawings wherein:

FIG. 1 is a rear perspective view of a camera;

FIG. 2 is a simplified mechanical schematic of one embodiment of thewarning system;

FIG. 3 is a partially cut away rear view of the camera including amechanical embodiment of my warning system;

FIG. 4 is a section view through the mechanical embodiment of FIG. 3;

FIG. 5 is a section view through another embodiment of my warningsystem; and

FIG. 6 is a logic diagram of an electronic embodiment of my warningsystem.

DETAILED DESCRIPTION OF A FIRST EMBODIMENT

FIG. 1 is a rear perspective view of a camera 10 with its back 11 openexposing a portion of the film advancement mechanism 12 and itsreceptical 15 for temporarily receiving a conventional roll or canisterof film to view. Those skilled in the art will appreciate that thecamera depicted in FIG. 1 is similar to the single lens reflex camera ofthe 35 mm variety, for example, which is commonly used by both amatuerand professional photographers. Thus the camera typically includes aviewfinder 13, a film advancement lever 12a (which may be consideredpart of the film advancement mechanism 12), a film rewind knob 14, ashutter release button 16 and a button 17 which permits the back 11 tobe opened when operated. The camera's lens 22 is partially hidden fromview and would commonly include a aperture control disposed thereon. Aswill be seen, my invention is not limited to a 35 mm single lens reflexcamera unless otherwise set forth in the appended claims.

The camera of FIG. 1 differs in outward appearance from prior artcameras by the addition of a wheel assembly 20 which is adapted torotate in the direction of arrow B when a roll or canister of film isplaced in recepticle 15, threaded into mechanism 12 and advanced by therotation of lever 12a. Wheel assembly 20 preferably includes twosprocked gears 20A having teeth 21 for engagement with the registrationholes provided along the edges of film, especially 35 mm film.

Turning now to FIG. 2, there is depicted a simplified mechanicalschematic of one embodiment of my warning system. The wheel 20, whichrotates as the film moves into a position for taking a picture, rotatesa warning indicator 25 mounted on a rod 30 via a rear train 22. Afriction clutch 23 may be provided between the indicator 25 and wheel 20to permit slippage of the gear train if the warning indicator reachesits limit of travel and further rotation of wheel 20 is needed.Preferably, of course, the limit of travel of indicator 25 is reachedwhen the film is normally advanced by selecting an appropriate gearratio for gear train 22. A release mechanism 24 is also coupled betweenthe indicator 25 and the wheel 20 mechanism 24 permits the warningindicator to return to its warning position in response to operation oflink 27. Link 27 is coupled via a lever 28 to the shutter release button16 (also shown in FIG. 1) .Iadd.or alternatively to button 17.Iaddend..A spring 26 urges the clutch 23 normally into engagement, but link 27bears on mechanism 24 as button 16 is operated and thereby disengagesclutch 23. Indicator 25 is then free to return to its warning positionunder the influence of a spring 29. When the film is advanced rotatingwheel 20 in the direction of arrow B, the warning indicator 25 willrotate in the direction of arrow c against the action of spring 29.

FIG. 3 depicts the viewfinder 13 of camera 10 and my warning system. Inthe viewfinder's window can be seen the scene depicted in front ofcamera 10 in FIG. 1. The warning indicator 25 appears in the viewfinderat numeral 25a. When wheel 20 is rotated in the direction of the arrow,indicator 25 will rotate to the position denoted by numeral 25b, whichis out of the operators field of vision in viewfinder 13. The gear train22 is depicted in the section view of FIG. 4. Idler gear 22b assuresthat wheel 20 and shaft 30 will both rotate in the same direction inthis embodiment. In FIG. 3 only the upper sproket gear 20a is shown forease of illustration.

In lieu of coupling link 27 to the shutter release button, somepracticing the present invention may desire to couple link 27 to button17 whereby the warning indicator would be reset only after the back 11is opened to replace the film, for example. Also, in lieu of placing thewarning indicator in the vicinity of the viewfinder 13, others maydesire to place it elsewhere on the camera.

DETAILED DESCRIPTION OF A SECOND EMBODIMENT

My second embodiment is similar to my first, except that instead ofutilizing a separate warning indicator I utilize the existing lever 12aas a warning indicator. This embodiment is shown by FIGS. 1 and 5, FIG.5 being a section view through the upper portion of the film advancementmechanism. Rod 30 includes a pin 31 and rod 30 is disposed adjacent toshaft 12b of mechanism 12a. Shaft 12b rotates counterclockwise in thisembodiment when lever 12a is rotated in a counterclockwise fashion. Pin31 is arranged to engage a detent 32 formed by member 12c on shaft 12bunless rod 30 is rotated moving pin 31 to the position 31' denoted bythe dashed lines. Pin 31 on rod 30 moves in much the same fashion asindicator 25 and thus will move to position 31' upon proper advancementof the film. If the film has not properly advanced, full advancement ofthe film advancement mechanism lever 12a is not possible, therebywarning the operator of improper film advancement.

DETAILED DESCRIPTION OF A THIRD EMBODIMENT

My third embodiment utilizes primarily electronic circuit techniques toprovide a warning indication. An electronic latch 40 is set by theclosure of a switch 41 and reset by the closure of a switch 42. Switch41 is preferably arranged to open when the back 11 is properlyinstalled, however, it could also be arranged to operate in response tooperation of the shutter release button 16. Switch 42 is preferablyoperated by rotation of wheel assembly 20. Latch 40 causes warningindicator 44 to light when in the set state, provided, of course, that aswitch 43 in series with indicator 44 is closed (assuming switch 43 iseven utilized). Switch 43 is preferably closed upon partial depressionof release button 16, such as occurs when the camera operator attemptsto take a picture. The warning indicator will then light if latch 40 isset indicating that the film has not properly advanced. Of course,switch 43 may be eliminated if desired, but switch 43 is preferablyemployed to reduce the consumption of electrical energy by the circuitof FIG. 5. The warning indicator 44 may be provided by a light emittingdiodes positioned in the viewfinder, for example.

Having described my invention with respect to certain embodimentsthereof, modification will now suggest itself to those skilled in theart. The invention itself is not to be limited to the embodimentsdescribed, except as set forth in the appended claims.

What is claimed is:
 1. In a camera having a body .[.with aviewfinder.]., .Iadd.a shutter release means, .Iaddend.a recess fortemporarily receiving a roll of film and a take-up mechanism foradvancing the film from said roll, the film having a plurality ofregistration holes situated along at least one edge thereof, .[.theimprovement.]. .Iadd.a warning system independent of said shutterrelease mechanism for warning an user of the camera of the improperthreading of the film into said take-up mechanism, said warningmechanism .Iaddend.comprising a sprocket wheel assembly having sprocketsfor engagement with .Iadd.the .Iaddend.registration holes in the film,said wheel assembly rotating in response to advancement of the film,.[.a flag moveably.]. .Iadd.a rotatably mounted indicator.Iaddend.disposed in the .[.field of view of said viewfinder.]..Iadd.body .Iaddend.and means for moving said .[.flag out of the view ofsaid viewfinder.]. .Iadd.indicator .Iaddend.in response to the rotationof said assembly .Iadd.when the film is properly threaded into saidtake-up mechanism, said indicator remaining stationary when said shutterrelease means is operated.Iaddend..
 2. The camera according to claim 1,wherein the body includes .Iadd.a viewfinder and .Iaddend.a coverassembly for providing access to said recess, and said .[.flag.]..Iadd.indicator .Iaddend.is moved into a warning position in .[.thefield of view of.]. the viewfinder in response to disengagement of thecover assembly.
 3. In a camera having a body with a recess fortemporarily receiving a roll of film, shutter release button and atake-up mechanism for advancing the film from said roll, the film havinga plurality of registration holes situated along at least one edgethereof, the improvement comprising a sprocket wheel assembly havingsprockets for engagement with registration holes in the film, said wheelassembly rotating in response to advancement of the film; a first switchoperated in response to depression of the shutter release button; asecond switch operated in response to rotation of said wheel assembly; alatch which is set in response to operation of the first switch andreset in response to the operation of said second switch and a warningindicator responsive to the state of said latch for providing a warningindication when said latch is set.
 4. The camera according to claim 3further including a third switch operated in response to partialdepression of said release button and wherein said warning indicatorprovides a warning indication when said latch is set and said thirdswitch is operated.
 5. The camera according to claim 3 wherein saidwarning indicator emits visible light when providing a warningindication. .[.6. In a camera having a body with a recess fortemporarily receiving a roll of film and a take-up mechanism foradvancing the film from said roll, the film having a plurality ofregistration holes situated along at least one edge thereof and thetake-up mechanism including a film advancement lever, the improvementcomprising a sprocket wheel assembly having sprockets for engagementwith registration holes in the film, said wheel assembly rotating inresponse to advancement of the film and means coupled to the wheelassembly for warning the operator of camera non-advancement of saidfilm, said warning means including means for inhibiting the normalmovement of said lever in response to the non-rotation of said wheel..].In a camera having a body with a viewfinder, .Iadd.shutter releasemeans, .Iaddend.means for temporarily receiving a roll of film and meansfor advancing the film from said roll, .[.the improvement.]. .Iadd.awarning system for warning an user of the camera of the improperthreading of the film into said advancing means, said warning mechanism.Iaddend.comprising: an assembly provided independently of the filmadvancing means and operatively in contact with the film for movement inresponse to advancement of the film and for non-movement in response tonon-movement of the film; a flag moveably disposed in a given positionwithin the field of view of said viewfinder; and means for moving saidflag out of .[.same.]. .Iadd.said .Iaddend.given position in response tothe movement of said assembly .Iadd.when the film is properly threadedinto said take-up mechanism, and for maintaining said flag in a fixedposition when the shutter release means is operated. .Iaddend.
 8. Acamera according to .[.claims.]. .Iadd.claim .Iaddend.1, .[.3 or 6,.].wherein said wheel assembly remains stationary in response tonon-advancement of said film. .Iadd.9. A camera according to claim 3wherein said wheel assembly remains stationary in response tonon-advancement of said film. .Iaddend. .Iadd.10. In a camera having acase with a chamber for receiving a roll of film and a take-up mechanismfor advancing the film frame by frame, the film having a plurality ofregistration holes along at least one edge thereof, a warning systemindependent of the shutter release mechanism for warning an user of thecamera of the improper threading of the film into said take-upmechanism, said warning mechanism comprising:(a) an assembly havingspockets adapted to engage the registration holes in the film, saidassembly moving in response to advancement of the film; (b) a window insaid case; (c) a rotation warning device disposed internally of saidcase and viewable through said window, said rotational warning devicehaving two display conditions, a first display condition warning theoperator of the camera of the non-advancement of the film and a seconddisplay condition advising the operator of the proper advancement of thefilm; and (d) means independent of the shutter release mechanismoperationally coupling said sprockets to said warning device forrotating said warning device from said first display condition inresponse to movement of said assembly when the film is properly threadedinto said take-up mechanism, said warning device not rotating when saidshutter release mechanism is operated. .Iaddend.